Sphere making machine



Oct. 6, 1964 A. c. RAY 3,151,419

SPHERE MAKING MACHINE Filed March 8, 1963 3 Sheets-Sheet l ES A f0 INVENTOR.

TOIe/VEYS.

Oct. 6, 1964 A. c. RAY

SPHERE MAKING MACHINE 3 Sheets-Sheet 2 Filed March 8, 1963 m 1 mm w Oct. 6, 1964 A. c. RAY 3,151,419

SPHERE MAKING MACHINE Filed March 8, 1963 3 Sheets-Sheet 3 INVEN TOR. ARCH/E c. 24%

United States Patent SFHERE MAKING MACHXNE Archie Q. Ray, Rte. 1, Box 15, Powell, Wye. Filed Mar. 8, 1963, Ser. No. 263,967 2 Claims. (til. S1--73) This invention relates to new and improved machines for grinding objects to a spherical form, and more particularly to a ball grinding machine for use 1n grind ng spherical objects of a substantial size, such as bowling balls, or the like, as well as spherical objects made from semi-precious stones, such as agate, or similar material.

A main object of the invention is to provide a novel and improved ball grinding machine which is relatively simple in construction, which is of high efficiency, and which is easy to adjust. I

A further object of the invention is to provide an improved ball grinding machine which is relatively inexpensive to fabricate, which is durable in construction, which is adjustable to provide the grinding pressure on the object being abraded for obtaining maximum efficiency of operation, and which is provided with interchangeable grinding heads so that it can be employed to grind a wide range of sizes of spherical objects.

Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:

FIGURE 1 is a perspective view of an improved ball grinding machine constructed in accordance with the present invention.

FIGURE 2 is an enlarged longitudinal vertical cross sectional view taken through the ball grinding machine of FIGURE 1.

FIGURE 3 is a horizontal cross sectional view taken substantially on the line 33 of FIGURE 2.

FIGURE 4 is a transverse vertical cross sectional view taken substantially on the line $4 of FIGURE 2.

FIGURE 5 is a transverse vertical cross sectional View taken substantially on the line 5--5 of FIGURE 2.

FIGURE 6 is an enlarged fragmentary vertical cross sectional view taken substantially on the line 6-6 of FIGURE 5.

FIGURE 7 is a fragmentary vertical cross sectional view generally similar to FIGURE 6 but showing a modification.

Referring to the drawings, and more particularly to FIGURES 1 to 6, It generally designates an improved ball grinding machine constructed in accordance with the present invention.

The machine 11 comprises a frame 12 having vertical angle bars 13 constituting the corner portions of the frame, the angle bars being connected at the opposite sides of the frame by longitudinally extending tie rods 14, said tie rods being rigidly interconnected by transversely extending cross bars 17 and I8.

Rigidly secured on the cross bars 17 and 18 at one end portion of the frame 12 is a longitudinally extending bracket member 19 which is generally I-shaped in cross section and which is provided with a base flange 20 which is horizontally secured on the mid portions of the cross bars 17 and 18 and with the upwardly and inwardly inclined top flange 21 which extends upwardly and inwardly at an acute angle to the horizontal, for example, at an angle of approximately the top flange 21 being connected to the bottom flange 24 by the vertical web 22. Secured on the top flange 21 is the longitudinally extending housing 23 of substantially rectangular cross section, said housing having the fixed end walls 24 and 25. Slidably and rotatably mounted in said end walls is the upwardly and inwardly inclined shaft 26, said shaft being biased upwardly and inwardly by a coiled spring 27 which surrounds the shaft at its lower portion, bearing between a stop collar 28 secured on the shaft and the adjacent end wall 25, the opposite end portion of the shaft being provided with a stop collar 29 which is urged against the end wall 24 by the action of the coiled spring 2'7.

Secured on the lower end of the shaft, namely, the end of shaft 26 adjacent the end wall 25 is a drive pulley 30. Secured on the opposite end of the shaft, namely, the end of the shaft 26 adjacent the end Wall 24 is a cup-shaped grinding head 31.

Grinding head 31 is provided with the annular interior abrasive surface 32. The grinding head 31 is detachably secured on the inner end of shaft 26, for example, by being threaded thereon and detachably secured thereto by a set screw 33. By loosening the set screw 33 and unscrewing the head 31, said head may be removed and replaced by another grinding head of the same general construction but of different size, in accordance with the size of the spherical article to be ground by the machine.

As shown in FIGURE 1, the cross bars 17 and 18 are fixedly secured to the longitudinal rods 14 by clamping screws 34, the rods 14 being similarly fastened to the upstanding corner posts 13 by clamping screws 35. The cross bars 15 and 16 are slidable on the longitudinal rods 14, and are rigidly interconnected at their top surfaces by a longitudinally extending bracket member 36 similar to the bracket 19 but reversed in direction. Thus, the bracket member 36 is provided with the base flange 37 which is rigidly connected to the intermediate portions of the top surfaces of the cross bars 15 and 16. Said bracket member is further provided with the upwardly and inwardly inclined top flange 3% which is rigidly connected to the bottom flange 37 by the integral web 39. The top flange 38 extends upwardly and inwardly at the same angle as the top flange 21 of the bracket member 19. Rigidly secured on the top flange 38 is the generally rectangular longitudinally extending housing 46 having the end walls 41 and 42. A shaft 43 extends longitudinally through the housing 49, being slidably and rotatably mounted in the end walls 41 and 4-2 and being provided at its inner end with a grinding head 44, similar to the grinding head 31, and being provided at its outer end with the drive pulley 45 which is similar to drive pulley 30. As shown in FIGURE 6, the shaft 43 is biased upwardly and inwardly, namely, toward the left, as viewed in FIGURE 2, by a coiled spring 47 which surrounds the shaft adjacent the wall 42, hearing between the wall 42 and the end wall 48 of an adjustable abutment sleeve 49. The abutment sleeve 49 is internally threaded, being threadedly engaged on an externally threaded collar member 59 which is mounted on the shaft 43 and which is clampingly secured thereto by a set screw 51. The tension of the spring 47 may be adjusted by adjusting the sleeve member 49 on the collar member 50. Thus, to increase the spring tension, the sleeve member 49 is rotated in a direction to move it to the right, as viewed in FIGURE 6, relative to the collar member 59. To reduce the spring ten sion, the sleeve member 49 is adjusted in a direction to move it to the left, as viewed in FIGURE 6.

Leftward movement of the shaft 43 is limited by a stop collar 53 secured on the shaft 43 inwardly adjacent the end wall 41. Righward movement of shaft 4-3 is resiliently opposed by the coiled spring 4'7.

The spacing of the bracket member as may be adjusted with respect to the bracket member 19 by the provision of a longitudinally extending adjusting screw 54 which is rotatably connected to the cross bar 17 and which is threadedly engaged through the cross bars 15 and 16. The outer end portion of the screw 54 is journaled in a transversely extending-vertical plate member 55 rigidly secured to the top portions of the vertical corner posts 13, 13 at the end of frame 12 adjacent bracket 36, a hand wheel 56 being secured on the end of the shaft 54 for rotating same. As will be readily apparent, by rotating the hand wheel es, the screw 54 moves cross bars and 16 longitudinally, whereby the bracket member 36 is similarly moved, so that its spacing from the opposing bracket member 19 may be adjusted.

As will be presently explained, the spacing between the bracket members 19 and 36 is adjusted so that an object 57 to be spherically ground will be engaged between the abrading surfaces 32 of the heads 31 and 44 with sufficient clamping force to develop tension in the coiled springs 27 and 47. As previously mentioned, the degree of tension provided by the coiled spring 47 may be adjusted by suitably positioning the sleeve member 49, which will establish the degree of resistance to outward movement acting on the shaft 43.

Designated at 58 is a longitudinally extending shaft which is journaled at one end portion in 2. depending intermediate portion 59 of cross bar 18 and at its other end portion in a transversely extending vertical plate member 72 rigidly connected to the upstanding frame corner posts 13 at the end of the frame adjacent the bracket member 19. A large pulley 73 is mounted on the outer end of the shaft 5%, being drivingly coupled by a V-belt 74 to a relatively small driving pulley 75 on the shaft of an electric motor 76 mounted on the base portion 12. A pulley 61 is secured on the shaft 58 between plate 72 and cross bar portion 5?, being drivingly coupled by a V-belt 62 to the drive pulley of shaft 26. Also secured on shaft 58 is a gear 77 which is in meshing engagement with a similar gear 78 mounted on a longitudinally extending shaft 79 journaled in depending portion 59 of cross bar 18 and in a similar depending portion 60 of cross bar 17. Shaft 7h is provided with a reduced squared portion 63 which is slidably but non-rotatably received in a squared sleeve portion 64 of a shaft 65 which is journaled in a depending portion 67 of cross bar 15. The squared portion 64 is rotatably supported in a depending portion 66 of cross bar 16. A stop collar 69 is secured on the shaft 65 inwardly adjacent said depending portion 7, and a similar stop collar 68 is secured on the squared sleeve portion 64 adjacent the depending portion 66 of cross bar 16 to limit endwise movement of shaft 65 and its squared portion 64. As will be readily apparent, the assembly comprising bracket 36 and cross bars 15 and 16 may be moved longitudinally relative to the shaft 79, but the shaft as will remain drivingly coupled to the shaft 79 because of the driving connection provided by squared shaft portion 63 and the squared sleeve 64 of shaft 65.

Secured on the outer end portion of shaft 65 is a pulley 70 which is drivingly coupled by a V-belt 71 to the pulley 45 of shaft 43, establishing a driving connection thereto similar to that provided for the shaft 26, but rotating shaft 43 in a direction opposite to the direction of rotation of shaft 26 because of the reversal provided by the meshing gears 77 and 78.

Drive belt 62 is maintained in proper working tension by tensioning means comprising a. tensioning arm 80 pivoted at 81 to the cross bar 6%, the arm 81 being provided at its end with a tensioning roller 82 engageable against the inside of the belt 62 and being held thereagainst by an abutment screw 83 threaded through the web 22 of bracket member 19 and being engageable with an upstanding lug 84 provided on the intermediate portion of arm 30. Similar belt tensioning means is provided for the drive belt 71, comprising a tensioning arm 85 pivoted at 86 to the cross bar 16, the arm 85 being provided at its end with a tensioning roller 87 which is engageable inside the belt 71, being held thereagainst by an abutment screw 39 threaded through the web 39 of bracket member 36 and being engageable with an upstanding lug 38 provided on the intermediate portion of the arm $5.

in operation, the object to be ground to spherical form, for example, the object 57, is positioned between the opposing cup-shaped members 31 and 44, said cup-shaped members containing suitable abrasive material, shown for 4 example, at 90, and the hand wheel 56 is operated to cause the abrading surfaces 32 of the heads to engage against the object with suiiicient force to place the springs 27 and 47 under tension. The degree of tension may be adjusted by adjustment of the sleeve 49, as above described. When the motor 76 is energized, the shafts 58 and 79 rotate in opposite directions, causing the heads 31 and 44 to similarly rotate in opposite directions, providing abrading action at the surfaces 32 of the heads, which causes the object 57 to tumble between the cup-shaped members 31 and 44 with the desired abrasion of its exterior surface. By the provision of the springs 47 and 27, the heads are relatively yieldable so that the cup-shaped members 31 and 44 pass over high spots, but in so doing, increase the tension in the springs, which similarly increases the grinding action. When the surface of the object 57 is relatively irregular, the head 44 tends to move axially against the tension of the spring 47, whereas the head 31 tends to move axially against the tension of the spring 27.

As previously mentioned, the heads 31 and 44 may be readily changed in order to accommodate objects of different sizes.

As shown in FIGURE 7, means may be provided to limit the extension of the shaft 43 toward the object being ground under the force of the spring d7, whereby to prevent the objcct from being ground to smaller than the desired diameter. Thus, a stop collar 91 may be provided on the shaft 43, providing the abutment means for the inner end of the spring 47, the opposite end of the spring bearing against the wall 42, as in the previously described embodiment of the invention. An adjustable sleeve member, shown at 49, may be mounted on the shaft 43, the sleeve member being internally threaded and being threadedly engaged on an externally threaded collar 50 secured on the shaft 43, the sleeve member 49 having the fixed end wall 43' which is engageable against the end flange 92 of the bearing bushing 93 provided in the wall 41. Thus, when the end of sleeve 49' and its end wall 48' engage against the bushing flange 92, no further inward extension of the shaft 43 may take place. FIGURE 7 illustrates the adjusted position of the sleeve 49' wherein no endwise movement whatsoever of shaft 43: may take place, since the position of sleeve 49' allows no play of shaft 43, since said shaft 43 has a collar 1% which engages against the outside surface of wall 41. To provide a definite permissible amount of endwise movement, the sleeve 49' is backed off from the position thereof shown in FIGURE 7, namely, is rotated in a direction so as to move end wall 48 away from flange 92 by an amount corresponding to the desired amount of play of shaft 43. The object will then be initially engaged between the grinding heads 31 and 44 with the bracket member 36 adjusted to a position such that the collar 1% engages the wall ll, as in FIGURE 7. This will provide the desired pre-tension in the spring 47, and similarly in the spring 27 to develop the required grinding force on the object at the abrading surfaces 32. As the diameter of the object is reduced by the abrading action the spring 47 expands until finally the end of sleeve 4% and its end wall 48, come into engagement with the flange 92, preventing further extension of the shaft 43.

The arrangement illustrated in FIGURE 7 is particularly useful in grinding spherical objects to a definite specified size, for example, in grinding bowling balls.

While certain specific embodiments of an improved ball grinding machine have been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended clahns.

What is cla med is:

1. A ball grinding machine comprising a support, a pair of upstanding coplanar supporting brackets on said support, upwardly and inwardly inclined opposing shafts rotatably and slidably mounted on said brackets, respective cup-shaped grinding heads mounted on the inner ends of said shafts, each including an annular interior abrasive surface, an abutment collar on one of the shafts, a coiled spring on said one shaft bearing between said abutment collar and the supporting bracket on said one shaft, an externally threaded collar rigidly secured on the other shaft, a cup-shaped abutment sleeve on said other shaft theadedly engaged on said last-named collar, a coiled spring on said other shaft bearing between the cup-shaped sleeve and the supporting bracket or" said other shaft, said coiled springs acting to bias said shafts inwardly, said heads being adapted to receive an object therebetween with the annular abrasive surfaces thereof urged into rubbing contact with said object by said coiled springs, and means drivingly connected to said shafts and rotating them in opposite directions. v

2. A ball grinding machine comprising a support, a

pair of upstanding coplanar supporting brackets, one of 20 said brackets being rigidly secured to said support, means slidably supporting the other bracket for movement in the plane of said brackets, an adjusting screw journaled to said support extending in the same direction as said plane and being threadedly engaged with said other d bracket for adjusting the same in said plane, upwardly and inwardly inclined opposing shafts rotatably and slidably mounted on said brackets, respective cup-shaped grinding heads mounted on the inner ends of said shafts, each including an annular interior abrasive surface, an abutment collar on one of the shafts, a coiled spring on said one shaft bearing between said abutment collar and the supporting bracket of said one shaft, an externally threaded collar rigidly secured on the other shaft, a

cup-shaped abutment sleeve on said other shaft threadedly engaged on said last-named collar, a coiled spring on said other shaft bearing between the cup-shaped sleeve and the supporting bracket of said other shaft, said coiled springs acting to bias said shafts inwardly, said heads being adapted to receive an object therebetween with the annular abrasive surfaces thereof urged into rubbing contact with said object by said coiled springs, and means drivingly connected to said shafts and rotating them in opposite directions.

References Cited in the file of this patent UNITED STATES PATENTS 1,950,785 Capps Mar. 13, 1934 2,479,898 Beaudette Aug. 23, 1949 3,024,578 Mushkin Mar. 13. 1962 

1. A BALL GRINDING MACHINE COMPRISING A SUPPORT, A PAIR OF UPSTANDING COPLANAR SUPPORTING BRACKETS ON SAID SUPPORT, UPWARDLY AND INWARDLY INCLINED OPPOSING SHAFTS ROTATABLY AND SLIDABLY MOUNTED ON SAID BRACKETS, RESPECTIVE CUP-SHAPED GRINDING HEADS MOUNTED ON THE INNER ENDS OF SAID SHAFTS, EACH INCLUDING ANNULAR INTERIOR ABRASIVE SURFACE, AN ABUTMENT COLLAR ON ONE OF THE SHAFTS, A COILED SPRING ON SAID ONE SHAFT BEARING BETWEEN SAID ABUTMENT COLLAR AND THE SUPPORTING BRACKET ON SAID ONE SHAFT, AN EXTERNALLY THREADED COLLAR RIGIDLY SECURED ON THE OTHER SHAFT, A CUP-SHAPED ABUTMENT SLEEVE ON SAID OTHER SHAFT THEADEDLY ENGAGEMENT ON SAID LAST-NAMED COLLAR, A COILED SPRING ON SAID OTHER SHAFT BEARING BETWEEN THE CUP-SHAPED SLEEVE AND THE SUPPORTING BRACKET OF SAID OTHER SHAFT, SAID COILED SPRINGS ACTING TO BIAS SAID SHAFTS INWARDLY, SAID HEADS BEING ADAPTED TO RECEIVE AN OBJECT THEREBETWEEN WITH THE ANNULAR ABRASIVE SURFACES THEREOF URGED INTO RUBBING CONTACT WITH SAID OBJECT BY SAID COILED SPRINGS, AND MEANS DRIVINGLY CONNECTED TO SAID SHAFTS AND ROTATING THEM IN OPPOSITE DIRECTIONS. 